Volkswagen faced its first mass lawsuit in the English courts on Monday over the "dieselgate" emissions scandal, with around 90,000 drivers demanding compensation from the German auto giant.

In what could be the largest case of its kind in England, the High Court will decide whether software installed in VW, Audi, Seat and Skoda diesel vehicles was designed to cheat clean air laws.

In 2015, Volkswagen admitted to manipulating 11 million vehicles worldwide to fool emissions tests, including almost 1.2 million in Britain.

The scandal has already cost the group more than 30 billion euros ($33 billion) in fines, compensation and legal costs, mostly in the United States.

Tom de la Mare, the lawyer representing the claimants, told the London court that VW engines were "optimised to minimise the amount of pollutants" in emissions tests.

This meant the vehicles operated in a "completely different way in the street to how it operated in the test".

German car maker Volkswagen (VW) faces compensation demands from around 90,000 drivers in Britain in connection with the "dieselgate" emissions scandal
German car maker Volkswagen (VW) faces compensation demands from around 90,000 drivers in Britain in connection with the "dieselgate" emissions scandal AFP / RONNY HARTMANN

He added: "It is difficult to think of a more obvious cheat than the one VW used."

Over the next two weeks, the court will hear submissions to determine whether VW's software was a "defeat device" under EU regulations and also, whether the court is bound by the German regulator's previous finding that it was.

Further hearings would be required to establish any damages that might be due, according to law firm Slater and Gordon, which represents 70,000 claimants.

In a statement before Monday's hearing, a VW spokeswoman said: "Volkswagen Group continues to defend robustly its position in the High Court in London.

"It remains Volkswagen Group's case that the claimants did not suffer any loss at all and that the affected vehicles did not contain a prohibited defeat device."